I know this sounds weird, but to get the signature to work you first have to delete your avatar. There is a thread about this on the forum somewhere. It took me a while to get mine working, but when I deleted the avatar it worked. Then you can add the avatar back.

Still isn't working

I have tried logging out and in several times, I have deleted my avatar. I have changed the HTML source code several times. I don't know. Any other advise? When I go to geocaching.com and create my banner this is the exact code: Obviously this isn't what I have in my sig but the source url should be the same.